Alas, the --disable-checking and STAGE1_CFLAGS="-O2 -g" (which I was
already doing) only decreased the bootstrap time by 10%. By far, the
longest bit of the bootstrap is building libjava.

Building libjava takes forever on any platform, relative to the rest of
the compiler build. That's why I often disable it, especially since I
don't use Java very much, and gcj even less often than Java in general.
Do you really *need* gcj on these embedded platforms?

Also, I don't really think that bootstrapping GCC directly on target
hardware is very useful -- except for testing GCC. I'd build GCC on
some fast workstation, even if I eventually wanted it to run native on
the target.